標題: | Compensation effect and differential capacitance analysis of electronic energy band structure in relaxed InAs quantum dots |
作者: | Chen, J. F. Chen, Ross C. C. Chiang, C. H. Hsieh, M. C. Chang, Y. C. Chen, Y. F. 電子物理學系 Department of Electrophysics |
公開日期: | 15-九月-2010 |
摘要: | The use of a differential capacitance technique for analyzing the effect of strain relaxation on the electronic energy band structure in relaxed InAs self-assembled quantum dots (QDs) is presented. Strain relaxation is shown to induce a deep defect state and compensate the ionized impurity in the bottom GaAs layer, leading to a double depletion width and a long emission time. An expression of capacitance at different frequency and voltage is derived for analyzing the experimental data. It has been shown that the relationship between the low-frequency and high-frequency capacitances can be well explained by a Schottky depletion model with a compensated concentration in the bottom GaAs layer. A simple expression is presented to account for the modulation of the free electrons in the top GaAs layer. This capacitance analysis shows a long low-energy tail for the electron ground state, suggesting not very uniform strain relaxation. The results of this study illustrate a carrier compensation effect of the defect state on the electronic energy band structure near the QDs. (C) 2010 American Institute of Physics. [doi:10.1063/1.3467938] |
URI: | http://dx.doi.org/10.1063/1.3467938 http://hdl.handle.net/11536/32189 |
ISSN: | 0021-8979 |
DOI: | 10.1063/1.3467938 |
期刊: | JOURNAL OF APPLIED PHYSICS |
Volume: | 108 |
Issue: | 6 |
結束頁: | |
顯示於類別: | 期刊論文 |